General

Not surprisingly, this impressive phenomenon is determined by the availability of grazing, which in turn is dependent upon rainfall. Essentially the wildebeest are taking advantage of the strongly seasonal conditions, spending the wet season on the plains in the south-east, and the dry season in the woodlands of the north-west. However, the sheer weight of their numbers also plays an important role in shaping the environment to their needs.

Typically, the wildebeest head north-west from the short grass plains to the Western Corridor of the Serengeti and its Grumeti River. This watercourse is their first real obstacle and gigantic crocodiles are waiting for the hesitant wildebeest to stumble at the crossing. From Grumeti, the herds move north, often spilling over into the Klein's Camp Concession, before crossing the Kenyan border into the Masai Mara. Here again, they must cross a river, this time the Mara with its flotillas of hungry crocodiles. The mass of grunting wildebeest remain on the productive Mara grasslands until October or November. Then, as the storm clouds gather in the south, the vast herds return to their breeding grounds which, by the time they arrive, are once again green and lush and the cycle begins again.